1. Field of the Invention
The present invention relates to a display module, a display device, and a liquid crystal television set, and more particularly, it relates to a display module, a display device, and a liquid crystal television set each including a light guide plate guiding light received from a light source to a display cell and a holding member holding the light guide plate.
2. Description of the Background Art
A display module including a light guide plate guiding light received from a light source to a display cell and a holding member holding the light guide plate is known in general, as disclosed in Japanese Patent Laying-Open No. 2008-305576, for example.
The aforementioned Japanese Patent Laying-Open No. 2008-305576 discloses a liquid crystal display device including a rectangular light guide plate guiding light received from a cold-cathode tube (light source) to a liquid crystal display panel (display cell) and a frame (holding member) holding the light guide plate. In this liquid crystal display device, the light guide plate is provided in the form of a flat plate, and rectangular recess portions are formed on a first end surface of the light guide plate and a second end surface thereof opposed to the first end surface. Furthermore, in this liquid crystal display device, the frame is so formed as to surround respective end surfaces of the light guide plate in the form of a flat plate, and rectangular projecting portions are formed on portions of the frame corresponding to the recess portions of the light guide plate. In this liquid crystal display device, the recess portions of the light guide plate and the projecting portions of the frame are engaged with each other, whereby the light guide plate is held by the frame in the state where the light guide plate and the frame are in contact with each other. In this liquid crystal display device, the cold-cathode tube is opposed to an end surface on which no recess portion of the light guide plate is provided.
In the liquid crystal display device according to the aforementioned Japanese Patent Laying-Open No. 2008-305576, however, the light guide plate may expand or contract by heat generated from the cold-cathode tube (light source) or changes in temperature conditions and humidity conditions where the liquid crystal display device is placed. In this case, the light guide plate expands/contracts on the side of the light guide plate closer to the cold-cathode tube, employing portions of the light guide plate engaging with the holding member as basic points, and hence a distance (clearance) between the end surface of the light guide plate closer to the cold-cathode tube and the cold-cathode tube is changed. When the clearance between the cold-cathode tube (light source) and the light guide plate is changed, the light incidence efficiency with respect to the light guide plate is changed. Thus, the optical characteristics of backlight emitted from the light guide plate disadvantageously become unstable.